#!/bin/bash

awk -v OFS='\t' -v RS= '
((n = split($0, a, / {2,}| *\n/)) % 2) == 0 {
   # print header
   if (NR==1)
      for (i=1; i<=n; i+=2)
         printf "%s", a[i] (i < n-1 ? OFS : ORS)
   # print all records
   for (i=2; i<=n; i+=2)
      printf "%s", a[i] (i < n ? OFS : ORS)
}' | column -t -s $'\t'